Shortly after nitrogen and oxygen were first liquefied in the last 1800's, industrial production of liquid nitrogen and liquid oxygen was accomplished and they rapidly became important commodities for the steel and fertilizer industries. Economies of scale reduced the cost of liquid nitrogen and liquid oxygen to a few cents per liter. Thousands of tons of each are now produced per day for industrial purposes and are transported over large distances in tanker cars. They are also available to a wide class of users, in particular, those in university and industrial research laboratories, medical clinics and hospitals, world-wide. However, the quantities used by such individual researchers and doctors in these establishments are usually small, of the order of a few liters per day. While the cost of these cryogens at the source is small, distribution, storage losses and costs of purchasing in small quantities results in an end price substantially larger than the bulk price. This issue was partially addressed in the 1950's by the development of a laboratory scale closed cycle gas refrigeration machine as described by J. W. H. Kohler and C. O. Jonkers, in Philips Techn. Rev. 16, 69 (1954). These machines were much smaller than the large industrial liquefiers for liquefaction of air or nitrogen, but were not office machines. They draw almost 6 kW of power and produce over 140 liters of liquid air per day. This is several orders of magnitude larger than what would be needed for a doctor's office, or an individual researcher. A need has existed, therefore, for a much smaller liquefier capable of generating a few liters per day that could address the liquid nitrogen needs of dermatologists, materials scientists and chemists; the liquid oxygen needs for breathing-impaired patients; and needs for small quantities of other liquid cryogens.